


Rectangles Are Not Squares (But Squares Are Rectangles)

by softwhiskeyjack



Category: Fire Emblem: If | Fire Emblem: Fates
Genre: Background Male My Unit | Avatar/Zero | Niles, F/M, Fluff, Friends to Lovers, Kamui/Corrin Twins
Language: English
Status: Completed
Published: 2016-06-19
Updated: 2016-06-19
Packaged: 2018-07-15 22:06:36
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,414
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7240318
Author URL: https://archiveofourown.org/users/softwhiskeyjack/pseuds/softwhiskeyjack
Summary: <blockquote class="userstuff">
              <p>They went into this relationship like they did with everything else; together and at their own pace.</p>
            </blockquote>





	Rectangles Are Not Squares (But Squares Are Rectangles)

**Author's Note:**

> Anon prompt was: "Asdasxasxasx you literally are my most favorite fe writer ever! The words you use, the pacing, the e-mo-tion-!! All of it is phenomenal! :) It might be a bit troublesome, but could you consider writing a fmuxcyrus fic? About how their r/s evolved? :) And if you feel like it, maybe, you could also try including male kamui too? Maybe as fem kamui’s real brother/twin? You don’t have to though, sorry for being too, um, demanding…?? And thank you nonetheless! :)"
> 
> Archiving from Tumblr!

**I.**

She was twelve when she met him; he was fourteen, going on fifteen.

There was a celebration happening at the main castle in Nohr; it was an event to honor the birthday of their first prince, Marx. She had paid her respects to her big brother of course but, more importantly, this was a rare chance for her to see her twin brother, Corrin.

Even though they were twins they had been raised in separate places. She lived most of her life in the Northern Citadel while he lived his in the Southern Citadel. It was only during events like these, when both of them would be brought to the main castle, that they could see each other. Marx, understanding this, had given her permission to roam the castle grounds so long as she returned before the dinner and ball started.

And this was why she was currently sprinting down the hall with a handful of pastries clutched to her chest and being chased by an angry cook.

She rarely visited the main castle in Nohr so it was only natural for her to get lost, right? Just like it was natural for her to follow her nose to the delicious smells coming from the kitchens because being lost was hungry work. And if she decided to sample some of the pastries… well, who could blame her? It’s not like they needed that much. Marx didn’t even like sweets!

The cooks must not have recognized her though because when they caught her sneaking the pastries into her mouth they started to yell and threatened to spank her if they caught her. She was too terrified to stop and explain to them who she was, and so she just turned tail and ran with a handful of those pastries.

But back to her current predicament, she had just turned a corner when she nearly ran over another person. As it turned out though, with her small stature, she only collided into their chest and would have bounced off onto the floor had they not reflexively caught her by the shoulders.

“Woah there!”

“Sorry, ‘scuse me!” She squirmed out of their hold and tried to bolt down the hall again, but they stopped her by snagging her arm before she could pass them.

“Hey, wait a moment, I don’t recognize you. What are you doing running around in the royal wings?”

She looked back at the person with impatience and saw that he was a boy, barely older than her, with green eyes and a messy mop of hair. “I don’t recognize you either but you don’t see me stopping people randomly from going to where they need to go!”

“R-Randomly? You were the one who crashed into me and you never answered my question!” He spluttered in response. But then his eyes fell to the pastries clutched in her hands and narrowed, “Wait, are you a thief?!”

“What? No! How dare you accuse me of that! I’m a princess of Nohr.” She bristled at his skeptical look but, before she could do anything, they both heard the angry shouts of a cook in the distance. “Look, I don’t have the time to argue. You seem to know your way around this place. Hide me and I’ll split half of these with you.”

His mouth dropped open. “Are you trying to bribe me? A knight of Nohr?”

“Ugh, I’m trying to be nice. If you won’t accept this deal then I’m ordering you as a princess of Nohr to help me.” She stamped her foot.

“How do I even know you’re a princess?! You could be a thief and a liar!”

“Well, one of us has to be right. Are you really going to risk me being the right one? What would people say if they heard that you didn’t obey your princess’ orders?”

He was clearly torn on what to do but she only looked at him pointedly and then down the hall where the shouts of the cook were getting closer.

“… I can’t believe I’m doing this.” He finally muttered, running his free hand through his hair, before he lead her in the opposite direction. “Follow me!”

It was the start of a beautiful friendship.

(And of course, in the end, he took half of the pastries.)

**II.**

The waves of Nosferatu were endless and before she knew it she found herself surrounded and cut off from the rest of the army.

Kamui gritted her teeth as she parried a strong blow, the force of it making her legs buckle. Spinning to the side, she diverted the force down to the ground and then lunged forward to slam her elbow into the enemy’s chest. He, or maybe it, stumbled back from the blow and she seized the opportunity to swing her sword back up, slashing it wide open.

She paid no more attention to the enemy as it collapsed and used this chance to spin around desperately, trying to regain her bearings. “Corrin?!” She strained her ears for any reply but she couldn’t hear anything over the clashing of weapons and shouts.

And then the next wave of Nosferatu started to form again; their masked features showing nothing of what they thought about climbing over their fallen brethren to reach her.

“You guys sure are tenacious,” she muttered with more energy than she felt. Her arms were starting to shake from exhaustion and she was sure she had a bruised rib after receiving a shield bash that sent her sprawling to the ground. Only her quick reflexes had saved her from being stabbed back there.

“Kamui, get down!”

She reacted more to the familiarity in that voice than she did to the command and dropped immediately to the ground, wincing as she jarred her injuries. A javelin soared over her head in the next moment and pierced through a Nosferatu, pinning it the ground, before being followed by a war horse and its rider.

The two worked as one to cut down the surrounding Nosferatu, creating a wide circle of space around the three of them, before the rider leapt down and extended a hand to her.

“Silas?!” Kamui gaped as she took the offered hand and was yanked to her feet, “What are you doing here?!”

“I arrived with Lady Elise. We’re your reinforcements.”

“Elise is here too? Where?! Why?!”

“She’s safe with the main force. I’ll tell you more later but we need to hurry up and fall back to regroup with them.”

He was pushing her towards his mount but she dug her heels into the ground and grabbed him by the arm. “Wait, did you see Corrin anywhere?”

“Yes, he’s back with the main force as well.”

Kamui slumped with relief and allowed him to boost her up into the saddle. Silas jumped on behind her and started to guide his horse back the way they came.

“That idiot jumped into the fray without a strategy before we could stop him.”

“And so you followed him?” There was an odd tone to his voice.

“Are you implying that I’m an idiot too? It’s a sister’s job to take care of her brother! Wait a minute, you came to me in the middle of this too, what does that make you?”

“An idiotic knight who can’t abandon his equally idiotic princess.” She tried to lean her head back to look at him but he raised a hand to keep her still. “Don’t block my view. What would you do without me?”

“Well… I wouldn’t be covered in mud, that’s for sure.” Kamui yelped as he rapped her sharply on the head. He seemed a bit tenser than usual though and so she settled down with only minor grumbles, knowing that they were still in the middle of battle.

There was an uninterrupted stretch of silence as they retreated until she broke it.

“Hey, Silas…”

“Mm?”

“Thank you.” _For coming for me._

“Always.”

**III.**

The moment she entered the mess hall she knew that something suspicious was going on. Corrin never had a good poker face and the fact that he was studiously staring at his porridge (it couldn’t be that interesting) sent warning bells. But she couldn’t see anything out of place when she looked around.

With a mental shrug, she started to head to where Silas was sitting, until she found herself tripping over something. The tray in her hand, filled with food, was sent spilling onto the ground and she braced herself for the inevitable mess.

But she was suddenly grabbed by the shoulders and spun away. Exhaling sharply as she landed against a hard chest, she looked up to thank the person only to find herself staring straight into a lazy blue eye and a slow smirk.

Zero clicked his tongue, “You should be more careful.”

“I suppose it wouldn’t be very dignified for the army commander to be covered in a mess.”

“No,” he murmured, lowering his head and his voice, “On the contrary, I think you’d look irresistible as a mess.”

Kamui just stared at him.

He looked back at her with a straight face.

“T-That’s your latest line?” She started to snicker, “I’m so sorry, but that was awful.”

“A man has to try.”

“And, as always, thanks but no thanks.” She squeezed a hand in between them and laid it flat on his chest before shoving him back. He released her immediately and took an additional step back, raising his open hands in acknowledgement of his failure.

Kamui shook her head and turned to make her way to where Silas was sitting, occasionally giggling whenever she remembered Zero’s line, and took a seat in front of him. He gave her a curious and amused look, having watched the entire exchange.

“How many times does that make it?”

“I lost count somewhere around thirteen, or was it fifteen?”

Silas leaned his chin on his hand, “I’ve never seen him get so close to you before though. I wonder what made him try harder this time?”

She looked back over her shoulder and realized that Silas would only have been able to see Zero leaning intimately close to her and nothing else from his position. “I’m not sure, but I just thanked him and turned him down as usual.”

Zero must have left the moment she walked away since she couldn’t find him in the hall anymore. Interestingly enough, Corrin seemed to have disappeared immediately afterward too.

“I thought he was involved with–”

“Shh!” She whipped her head back around and leaned forward to cover Silas’ mouth with her hand. “I don’t think they want that to be known yet. At any rate, I know Zero’s not being serious and I don’t think he’s taking it seriously either, so I’m willing to play their game.”

Kamui settled back into her seat after having said that and then stole Silas’ half-eaten porridge, having spilled her own earlier through what she suspected was foul play. She ignored his halfhearted complaint.

**IV.**

“Really, Elise, it’s not a big deal. It’s just a small stain.”

“No, it’s not! I’m so sorry for spilling ink on you.”

Kamui found herself being pushed into the bath house despite her protests by her younger sister, Elise, who looked to be on the verge of tears.

“I can just change my clothes. It’s really not a problem.”

“This outfit is too cute to be ruined and we can still fix this,” Elise shoved her inside the change room for girls and started pulling Kamui’s clothes off, “I’ll bring you a change of clothes and get these ones washed immediately. Take your time, sister!” 

Like a hurricane, Elise disappeared before Kamui could get in another word, leaving her standing in the change room with just a towel wrapped around her. Kamui shook her head in exasperation and made sure her towel was secure before opening the door to enter the baths since there was nothing else to do now that she was in this situation.

But she froze upon seeing that someone was already occupying the baths. Said person also paused and stared back in shock.

“Silas?!” “Kamui!?”

“I’m sorry! I didn’t realize someone was already in here!” She immediately averted her eyes but she was sure the image of water droplets clinging onto damp skin was seared into her mind.

“… i-it’s not a big deal… but, uh, are you just going to continue standing there?”

“Well, you see…” She snuck a glance at him and noticed that his face seemed redder than usual, but that may just have been from the steam. “Elise kind of ran off with my clothes, so I can’t leave until she comes back with another pair.”

“Do I even want to know? Nevermind,” he shook his head. “I’ll just get out then and you can use the baths.”

“No, I’m the one intruding! You only take a bath after training to relax your muscles, right?” Kamui paused, feeling awful at having interrupted him, but then she thought of a great idea. “Wait, we can just share the bath like we used to!”

“H-Hold on! Even though we’re best friends, we’re no longer children, isn’t it a bit weird to share a bath?” Silas spluttered.

She could feel her own cheeks heating up but she already came this far. “If you’re that embarrassed you can just face the opposite way.”

Kamui entered the pool without another word and it was only when she was fully in the water that she dared to sneak another glance at Silas. He had turned resolutely to stare at the other wall and so all she could see of him was his back.

Although she was tense at first, and she suspected that he was as well, familiarity soon fell over her and she could find herself relaxing into the soothing water and silence.

“… this does bring back memories though,” Silas suddenly said, “Remember the time we decided to explore all the unused rooms in your castle? We were so dirty and completely covered in dust that the older knights just threw the both of us into the baths. I don’t think they even recognized you.”

“I probably looked like just another rascal to them like you, especially with the short hair I had.”

“Me? A rascal? You were clearly the bad one. Before I met you I was a proper knight.”

Kamui laughed loudly. “What was that thing you showed me in the baths again?”

She cupped her hands in the water in front of her, trying to recall what he showed her back in their childhood. But she suddenly felt a splash of water strike her on the back of the head. Spinning around she saw him grinning at her with both of his hands cupped in the water.

“Oh now you’ve started it…” She mimicked his gesture, cupping her hands in the water, and then shot a spray of water right into his face.

They spent the next few hours mock fighting each other until they both looked like prunes and were exhausted.

**V.**

“I’m starting to wonder if our camp has been poisoned or something. Everyone is acting really strange.” Kamui grumbled, “Did you know that the girls dragged me out on a shopping trip a few days ago? All I heard that entire day was “I think Silas would like this” or “Isn’t that Silas’ favorite color?” when you could care less about whether I wore blue or yellow.”

“Hmm… actually that’s not a bad idea. If you were to wear bright yellow then it’d be easier for me to find you on the battlefield.”

She tore a handful of grass from beside her and threw it onto him, grinning when he started spluttering. “I’d also be a target for all our enemies.”

The two of them were enjoying a rare moment of relaxation and had found this clearing, leading to the two of them lying down side by side in it. The sky was clear, the sun was shining, and a cool wind was blowing. All in all it was a beautiful day.

“Maybe it’s the season. It’s spring and so everyone wants to fall in love and get married.” Kamui mused before turning to face him, “Did you know that even my brother, Marx, took me aside to discuss with me marriage options?”

“No!” Silas gave her a look of mock horror, “How’d you get out of that one?”

“I told him that if he wanted to marry me off politically then he should find a candidate for himself first. You know, to lead by example and whatnot.”

“What’d he say to that?”

“He did that brow furrowing thing he usually does when he’s thinking about something seriously and then agreed! The last time I saw him I think he was considering a marriage for himself.” She smiled slyly at Silas.

“Kamui…” he said her name with a mixture of affection and exasperation.

They fell into a comfortable silence after that and she rolled back onto her back to stare at the clouds slowly drifting by. It was some time later when Silas raised his voice.

“Hey, Kamui…”

“Hm?”

“Have you ever thought about marriage and love? I just realized that while we’ve been talking about it you haven’t given any of your own opinions on it. Or are you not interested?”

"Mm… it’s not that I’m not interested… I think it’s more like I’m waiting for the right partner, maybe?”

“… Like?”

She carefully kept her eyes on the floating clouds, “… like someone who knows me better than myself. Someone who knows that I hate roses, love sweets, and am terribly grumpy in the mornings. Someone who doesn’t mind jumping straight into messes with me.” He was breathing steadily beside her and she forced herself to keep her own breathing and voice even as she continued on to ask, “What about you? I’ve noticed that you don’t seem to have any lady friends around, apart from me of course.”

“… I think I’m waiting for the right person too. Someone who’s too kind and headstrong for their own good. Someone who charges straight into problems without thinking and needs a knight in shining armor to save them.”

Kamui couldn’t stop the snort from escaping her and rolled over to look at him, only to find that he’s already turned himself to face her too.

“You don’t think that person is right for me?”

Was it just her imagination or was the distance between them growing smaller? And had his eyes always been such a dark shade of green? She swallowed past her dry mouth. “No, I just think it’s funny because I may know someone like that.”

“What a coincidence… because I think I may know someone for you too.”

She’s not sure who made the first move. Maybe no one did. Maybe, much like everything else they did, they both moved at the same time and closed the distance between them. She leaned forward and he came and their lips connected.

It was sweet and perfect and altogether too short. She kept her eyes closed as she felt him shift closer before they kissed again, and again, and again. Each kiss lasting longer and becoming deeper until she found herself pressed back against the grass with him leaning over her.

He was smiling the next time he leaned down to kiss her and she found herself laughing giddily into his mouth as she wrapped her arms around his neck. She learned that his breath would hitch if she scraped his lower lip with her teeth before soothing it with her tongue. He learned that she would make a soft and delightful noise if he cupped her face and stroked the space between her jaw and ear.

Unfortunately, they were suddenly interrupted by a faint “FINALLY!” shouted in the distance before someone shushed that person. Silas raised his head immediately, his cheeks becoming flushed, while Kamui groaned and dropped her head against the ground. She was also turning red.

“… tell me this isn’t happening…”

Silas’ only response was to chuckle lowly, his voice having gone husky from their activities.

“I’m so happy that my baby sister finally found someone!” The person in the distance continued on to say.

Kamui shot Silas an exasperated look before yelling back just as loud, “Don’t you know the meaning of privacy?! And you’re only older than me by a few minutes, idiot!”


End file.
